The purpose of the final work was to explain the way of building object-oriented web application with three-tier architecture and to point out the advantages and disadvantages of such a programming method in the application example for volunteering records with associations. The application was created in the Visual Studio Community 2015 tool. The object-oriented language C # is used. Through the theoretical part, the concepts are object-oriented programming, object-oriented programming concepts, C # language, Visual Studio tool, and MVC architecture. After that, the description of the
application itself, tables and images is explained, allowing a better insight into the code itself. With each part of the code the purpose of such programming is explained. In the application we have used two classes in models, the Udruga and the Volonter. In order for the application to work, the Udrugas and Volonters controllers are used. User Layout is created using HTML code and CSS code. For a more beautiful visual identity, a bootstrap is used that gives the application more dynamic and more comfortable operation. At the end of the final work, the appearance of a web application is displayed when it comes to the benefits and disadvantages and improvements that the application may have. The application is not for one association and as such is suitable for any volunteer association that want to afford the website. It also provides volunteer associations with insight into all volunteers working in a specific area, thus increasing mutual communication between associations.